Hello, welcome. My name is Mike, I will do my very best toassist you with your question.
Engine management light is on now, but was not on before.
This issue that you are having is really consistent with a shorting or failing ignition coil which will happen without warning,turn the light on,and cause this noise that you are getting.I don't believe from what you are describing that the issue is oil or internal engine related.The first step is to have the vehicle scanned for trouble codes.
This vehicle has a diesel engine which does not have an ignition coil.
On scanning, the code that comes up is a very general one that covers almost anything. So we have changed the fuel filter and added injection cleaner to the fuel. We have added engine flush to the oil, emptied it and put in fresh oil, although the oil was only changed 6 months ago. This car has just had a clutch, but cannot see any reason why that would have any bearing on the problem.
ANy other ideas?
the vehicle is still the same.